根据 Ramda 中数组中的值过滤集合 [英] Filter collection based on values in array in Ramda

问题描述

我有一组唯一值:

const 数组 = [1, 2, 4]

我有一组独特的对象:

const 集合 = [{类型:1，眼睛:'蓝色'}，{类型:2，眼睛:'棕色'}，{类型:3，眼睛:'绿色'}，{类型:4，眼睛:'蓝色'}]

使用 Ramda 如何从 collection 中提取类型包含在 array 中的所有对象?

预期结果:

<预><代码>[{类型:1，眼睛:'蓝色'}，{类型:2，眼睛:'棕色'}，{类型:4，眼睛:'蓝色'}]

解决方案

使用 R.innerJoin():

const array = [1, 2, 4]const collection = [{ 类型:1，眼睛:'蓝色'}，{ 类型:2，眼睛:'棕色'}，{ 类型:3，眼睛:'绿色'}，{ 类型:4，眼睛:'蓝色'}]const joinByType = R.innerJoin((o, 类型) =>o.type === 类型)const 结果 = joinByType(集合，数组)console.log(result)

<script src="https://cdnjs.cloudflare.com/ajax/libs/ramda/0.25.0/ramda.min.js"></script>

使用 R.propEq() 将 type 属性与数组中的类型 ID 进行比较.我们需要使用 R.flip() 因为innerJoin 传递对象在要比较的值之前.

const array = [1, 2, 4]const collection = [{ 类型:1，眼睛:'蓝色'}，{ 类型:2，眼睛:'棕色'}，{ 类型:3，眼睛:'绿色'}，{ 类型:4，眼睛:'蓝色'}]const joinByType = R.innerJoin(R.flip(R.propEq('type')))const 结果 = joinByType(集合，数组)console.log(result)

<script src="https://cdnjs.cloudflare.com/ajax/libs/ramda/0.25.0/ramda.min.js"></script>

I have an array of unique values:

const array = [1, 2, 4]

I have a collection of unique objects:

const collection = [
  { type: 1, eyes: 'blue'},
  { type: 2, eyes: 'brown'},
  { type: 3, eyes: 'green'},
  { type: 4, eyes: 'blue'}
]

Using Ramda how do I extract all the objects from collection where type is included in array?

Expected outcome:

[
  { type: 1, eyes: 'blue'},
  { type: 2, eyes: 'brown'},
  { type: 4, eyes: 'blue'}
]

解决方案

Use R.innerJoin():

const array = [1, 2, 4]
const collection = [{ type: 1, eyes: 'blue'},{ type: 2, eyes: 'brown'}, { type: 3, eyes: 'green'}, { type: 4, eyes: 'blue'}]

const joinByType = R.innerJoin(
  (o, type) => o.type === type
)

const result = joinByType(collection, array)

console.log(result)

<script src="https://cdnjs.cloudflare.com/ajax/libs/ramda/0.25.0/ramda.min.js"></script>

The same method in a more ramdaish way using R.propEq() to compare the type property with the type id from the array. We need to use R.flip() because innerJoin passes the object before the the value to compare to.

const array = [1, 2, 4]
const collection = [{ type: 1, eyes: 'blue'},{ type: 2, eyes: 'brown'}, { type: 3, eyes: 'green'}, { type: 4, eyes: 'blue'}]

const joinByType = R.innerJoin(R.flip(R.propEq('type')))

const result = joinByType(collection, array)

console.log(result)

<script src="https://cdnjs.cloudflare.com/ajax/libs/ramda/0.25.0/ramda.min.js"></script>

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